What is Atrial Fibrillation (AFib)? Symptoms, Causes, and Treatment

What is Atrial Fibrillation?

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Atrial fibrillation is a condition where the heart’s upper chambers (atria) exhibit irregular and usually very rapid (300-600 beats per minute) electrical activity. These chaotic electrical signals are transmitted irregularly to the lower chambers (ventricles), resulting in an irregular and often rapid heartbeat.

In a normal heart, the sinus node (the heart’s natural pacemaker) produces regular electrical signals. These signals first stimulate the atria, then the ventricles, ensuring the heart contracts in a regular and coordinated manner. In AFib, chaotic electrical signals are generated from multiple points in the atria, causing them to quiver (fibrillate).

Why AFib Matters

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AFib is not just an uncomfortable symptom but a condition with serious health consequences:

• Stroke risk: Stroke risk increases 5-fold in AFib patients
• Heart failure: Long-term AFib can weaken the heart muscle
• Quality of life: Palpitations, fatigue, and shortness of breath affect daily life
• Mortality: Increases death risk if left untreated

Types of Atrial Fibrillation

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AFib is categorized based on its duration and behavior:

1. Paroxysmal AFib

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• Starts spontaneously and terminates on its own within 7 days (usually within 48 hours)
• Normal rhythm (sinus rhythm) exists between episodes
• May progress to persistent AFib over time

2. Persistent AFib

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• Lasts longer than 7 days
• Does not terminate on its own; requires treatment
• Can be converted to normal rhythm with cardioversion (electrical or pharmacological)

3. Long-Standing Persistent AFib

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• AFib lasting more than 12 months
• Rhythm control can still be attempted
• Treatment becomes more challenging

4. Permanent AFib

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• Patient and physician have decided not to pursue normal rhythm
• Rate control and stroke prevention therapy are applied
• Rhythm control attempts have been abandoned

Symptoms of Atrial Fibrillation

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AFib symptoms vary greatly from person to person. Some patients feel no symptoms, while others experience significant complaints:

Common Symptoms

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• Palpitations: Heart beating fast, irregularly, or “fluttering”
• Fatigue: Unusual weakness and energy loss
• Shortness of breath: Especially during exertion
• Dizziness: Feeling lightheaded
• Chest discomfort: Pressure or tightness in the chest
• Exercise intolerance: Reduced physical activity capacity

Serious Symptoms (Require Emergency Care)

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• Severe chest pain
• Inability to breathe
• Fainting or feeling like you might faint
• Sudden weakness or numbness in face, arm, or leg (stroke sign)
• Difficulty speaking

Silent AFib

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Approximately 30% of patients have AFib without any symptoms. This “silent AFib” is often discovered incidentally during routine examination, ECG, or tests performed for other reasons. Silent AFib carries the same stroke risk, making regular health check-ups important.

Risk Factors

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Many factors increase the risk of developing AFib:

Non-Modifiable Risk Factors

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• Age: Risk increases significantly after 65
• Gender: More common in men, but women have higher stroke risk
• Family history: AFib in first-degree relatives increases risk
• Genetic factors: Certain gene variants create predisposition

Modifiable Risk Factors

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• Hypertension: The most important risk factor
• Obesity: Risk increases with body mass index
• Sleep apnea: Obstructive sleep apnea increases AFib risk 2-4 fold
• Alcohol consumption: Especially excessive alcohol (“holiday heart syndrome”)
• Smoking: Increases vascular disease and AFib risk
• Physical inactivity: Sedentary lifestyle
• Stress: Chronic stress and anxiety

Associated Conditions

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• Heart valve diseases: Especially mitral valve disease
• Coronary artery disease: Patients who have had heart attacks
• Heart failure: AFib can be both cause and consequence
• Thyroid diseases: Especially hyperthyroidism
• Diabetes: Type 2 diabetes increases AFib risk
• Chronic kidney disease

Complications of Atrial Fibrillation

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If left untreated, AFib can lead to serious complications:

Stroke

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The most feared complication of AFib. When the atria don’t contract properly, blood pools and clots can form. If this clot enters the bloodstream and travels to the brain, it causes a stroke.

• Stroke risk increases 5-fold in AFib patients
• AFib-related strokes are generally more severe
• Risk of permanent disability and death is high
• Risk can be greatly reduced with anticoagulant therapy

Heart Failure

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Prolonged rapid and irregular heartbeats tire and weaken the heart muscle:

• Tachycardia-induced cardiomyopathy can develop
• Heart’s pumping capacity decreases
• Shortness of breath, edema, and fatigue increase
• Can improve with rate control

Cognitive Impairment

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AFib also affects brain health:

• Silent brain infarcts (micro-strokes)
• Increased risk of vascular dementia
• Memory and concentration problems
• Cognitive decline

Diagnostic Methods

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AFib diagnosis is based on documenting the irregular heart rhythm:

Electrocardiogram (ECG)

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• Gold standard for diagnosis
• Absence of P waves and irregular R-R intervals
• Normal ECG may occur in paroxysmal AFib

Holter Monitoring

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• 24-48 hour continuous ECG recording
• To capture intermittent AFib episodes
• Correlation of symptoms with rhythm

Event Recorder

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• Worn for 2-4 weeks
• Patient activates when symptoms occur
• Ideal for capturing rare episodes

Implantable Loop Recorder

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• Small device placed under the skin
• Continuous monitoring for up to 3 years
• AFib investigation after cryptogenic stroke

Echocardiography

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• Evaluates heart structure and function
• Left atrial size (usually enlarged in AFib)
• Valve diseases
• Left ventricular function

Transesophageal Echocardiography (TEE)

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• Ultrasound performed through the esophagus
• Searches for clots in left atrial appendage
• May be required before cardioversion

Laboratory Tests

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• Thyroid function tests (TSH)
• Kidney function
• Electrolyte levels
• Complete blood count
• Liver function

Treatment Approaches

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AFib treatment targets three main goals:

1. Stroke prevention (anticoagulation)
2. Rhythm control (restoring normal rhythm)
3. Rate control (slowing heart rate)

1. Stroke Prevention (Anticoagulant Therapy)

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Most AFib patients require blood thinning therapy. Stroke risk is assessed using the CHA₂DS₂-VASc score:

CHA₂DS₂-VASc Score:

• C: Congestive heart failure (1 point)
• H: Hypertension (1 point)
• A₂: Age ≥75 (2 points)
• D: Diabetes (1 point)
• S₂: Stroke/TIA history (2 points)
• V: Vascular disease (1 point)
• A: Age 65-74 (1 point)
• Sc: Sex category (female) (1 point)

Anticoagulant Options:

Novel Oral Anticoagulants (NOACs):

• Dabigatran (Pradaxa)
• Rivaroxaban (Xarelto)
• Apixaban (Eliquis)
• Edoxaban (Savaysa)

Advantages: Fixed dose, no regular blood tests required, less intracranial bleeding

Warfarin (Coumadin):

• Vitamin K antagonist
• Requires regular INR monitoring (target 2-3)
• Preferred in mechanical valve patients

2. Rhythm Control

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Aims to restore and maintain normal sinus rhythm:

Cardioversion:

• Electrical cardioversion: Electric shock under anesthesia
• Pharmacological cardioversion: Rhythm correction with medication (amiodarone, flecainide, propafenone)

Antiarrhythmic Drugs:

• Amiodarone: Most effective, but more side effects
• Flecainide/Propafenone: For those without structural heart disease
• Sotalol: Beta blocker + antiarrhythmic effect
• Dronedarone: Similar to amiodarone, fewer side effects

Catheter Ablation:

• Pulmonary vein isolation
• Burning the foci that trigger AFib
• Success rate: 70-80% (higher in paroxysmal AFib)
• Recommended for drug-resistant patients
• May be first choice in young, symptomatic patients

3. Rate Control

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Aims to control heart rate (usually <110/min):

Medications:

• Beta blockers: Metoprolol, bisoprolol, carvedilol
• Calcium channel blockers: Diltiazem, verapamil
• Digoxin: Especially in heart failure
• Amiodarone: When other drugs are insufficient

AV Node Ablation + Pacemaker:

• For drug-resistant patients
• Heart block created by AV node ablation
• Permanent pacemaker implanted
• 100% rate control achieved

Lifestyle Modifications

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Lifestyle changes are critically important in AFib management:

Weight Control

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• Each 1-unit BMI decrease reduces AFib burden
• 10% weight loss significantly reduces AFib episodes
• Bariatric surgery can eliminate AFib in some patients

Alcohol Restriction

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• Alcohol can trigger AFib episodes
• No more than 1-2 drinks daily
• Some patients may need to quit completely

Exercise

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• Regular moderate exercise is recommended
• Excessive endurance exercise may increase AFib risk
• 150 minutes of moderate activity per week

Sleep Apnea Treatment

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• CPAP therapy improves AFib control
• Increases ablation success
• Sleep study should be performed

Stress Management

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• Meditation and yoga
• Deep breathing exercises
• Psychological support

Frequently Asked Questions (FAQ)

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When Should You See a Doctor?

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Seek medical help without delay in the following situations:

• New or worsening palpitations
• Chest pain or pressure
• Shortness of breath
• Dizziness or fainting
• Unusual fatigue
• Stroke symptoms (facial drooping, arm weakness, speech difficulty)

Regular cardiology follow-up is essential for successful AFib management. Early diagnosis and treatment prevent complications and preserve quality of life.

If you have questions about atrial fibrillation or would like to schedule an evaluation, please feel free to contact me.